#include <iostream>
using namespace std;

/**
 * 三角形形状
 */
int main() {
    int a, b, c;
    cin >> a >> b >> c;

    if (a > b) {
        swap(a, b);
    }
    if (a > c) {
        swap(a, c);
    }
    if (b > c) {
        swap(b, c);
    }

    if (a + b <= c) {
        cout << "illegal triangle";
    } else if (a * a + b * b == c * c) {
        cout << "right triangle";
    } else if (a * a + b * b < c * c) {
        cout << "obtuse triangle";
    } else {
        cout << "acute triangle";
    }
    return 0;
}